This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We will be conducting x-ray diffraction experiments on a variety of protein structure projects, including crystals of viral glycoproteins involved in paramyxovirus and herpesvirus entry processes. We will be bringing crystals soaked in heavy atom compounds, but only prefrozen, treated crystals (with microgram amounts of heavy atoms such as gold, platinum and mercury). All heavy atom treated crystals will be returned to Stanford for disposal. All of the proteins have been expressed using heterologous expression systems in cell culture using insect or mammalian cell lines - they are not derived from the growth of the original virus. The proteins are purified by affinity chromatography from the supernatants of the cells and do not pose any biohazard threat.